Artificial tooth.



No. 657,6I3.

T Patented s'e thu, I900. E. PIERREPONT.

ARTIFICIAL TOOTH.

(Application filed Kay 26, 1898.)

(No Model.)

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UNITED STATES PATENT Orr cn.

EVELYN PIERREPONT; o LoivDoN, ENGLAND.

ARTIFICIAL TOOTH.

SPECIFICATION forming part of Letters Patent No. 657,613, dated September 1 1, 1900.

Application filed Mt, 26, 1898. Serial No. 681,824 (No model.)

, Teeth; and I do hereby declare that the following is a full, clear, and exact description of the same. I

My invention relates to an improvement in mineral teeth of that type in which the teeth possess an internal recess, whereby they are secured to the plate or backing. The said improvement is also equally applicable to the attachment of portions of teeth, such as crowns, I

to their supports.

The method of attaching artificial teeth to the backing or plate support by forming such teeth with a basal cavity adapted to receive projections from the plate or support and so formed that the said teeth can be firmly secured on the said projections, thus avoiding the necessity for having pins or the like fixed in the said teeth before baking, is already known; but such teeth, constructed as hith erto known have not proved entirely satisfactory in use and are only capable of application instead of the ordinary pin-teeth to a limited extent.

My inventionconsists, essentially, in molding within a cavityin a plastic tooth or crown a spiral or other thread and in forming a keyway or slot or more than one such through the thread thus molded in the interior of the tooth. The tooth after molding in this form internally is then furnaced in the well-known manner and is ready for use.

'My invention not only provides a tooth having as strong and reliable a means of attachment to the plate as in the present system, but it also enables me to attach the tooth to positions in either metal or vnlcanite dental plates from which pin-teethhave been broken off, and this without refiring or revulcanizing the plate. I Moreover, in the case of flat teeth the backs or supports can be soldered to the base-plate and the mineral teeth afterward attached, thus making it unnecessary to retire the teeth, as would'b'e requisite in the case of ordinary front teeth.

In the case of crowns on gold or other sockets I attain the great advantage that I can undercut on two sides at least, so as to give a better hold. The recess in the tooth being filled with a suitable cement is then placed over the projection and the tooth pressed into its place. As soon'as the cement has set the tooth will be firmly fixed. In cases where pins are used the free ends of the pin or pins are also preferably headed, threaded, or grooved. The free space between the pin or pins and the aperture in the tooth is then filled with a suitable material, which completely closes the recess and beds firmly around the pins. When the cement has set, the pins are held quite as firmly in the tooth as if they had been furnaced into it, and there is no possibility of the pin unwinding, to-

gether with the block of cement, and thus becoming loosened, because the keyway or slot or slots in the threading prevents any rotary motion of the tooth upon the pin or pins.

In order to make my invention more clear, I have illustrated the same in the accompanying drawings, in which I have represented, 1n-

Figure 1, flat teeth in three modifications, showing the aperture for attachment at the back; Fig. 2, shoulder-teeth for vulcanite plates with the aperture at the back; Fig. 3, a section of c a front tooth for the lower jaw with the aperture at the base; Fig. 4, a similar section of a front tooth for the upper jaw; Fig. 5, a section ofv a metal collar with stud on top for detachable mineral crown, showing attachment in base; Figs. 6 and 7, diagrams of attachment of teeth to backing by means of a projection or pins, respectively.

Theapplication of my invention to the different patterns'of teeth lli)? obvious fro Iii the foregoing description and thedrawingsh It is desirable, as much as possible to place the support along the line of greatest resist-tance to the pressure on the tooth. Thus the basal position shown in Figs. 3 and 4 isein clined at an angle coinciding with the'lineof pressure upon the gum.

One great advantage of my improved con 'struction of teeth is that they may be used for repairing sets of teeth attached to plates or dentures'wherever an ordinary pin=tooth;

has been broken away from its support, leaving the pins in place.

the projecting-pins of the broken tooth-and secured in place in a few minutes without any cutting or alteration of the backing. These teeth are consequently applicable for all purposes for which it has hitherto been necessary to have at least two difierent types of teeth.

In conclusion, I desire to state that I am aware that artificial teeth have been constructed with screw-threaded pin-holes into which the threaded pin or pins havebeen In such a case atooth of my construction can easily be slipped over SQFGWQdyfiQd-I; make no claim to suchamethod oLa-ttachment; but r.

What I claim isv 1 y A mineral tooth having a recess spirally threaded, said threading interrupted by a slot. ,2; In com ina on, amin tooth having asp'irally-thre'aded recess, a slot interrupt ing said threading, a backing-plate having an undercut boss'projecting into the said recess,

and a filling securing the said tooth to the backing-plate.

- 1" 3,. incomhinatiou, amineral :toothhaving a spirally-threaded recess, a slot interrupting said threading,a grooved metal projecnan entering the said recess, a backing-plate attached to the said metal projection, and a filling-uniting the said tooth to the said projectio'n.

In witness whereof hand'in presence oftwo witnesses.

Y r EVEL N iEnnEPoNT. "Witnesses: i I

' HERBERT SEF'roN-JoNEs,

WALTER J. SKER N;

I have, hereunto set my 

